Electronic devices may include a variety of different input and/or output devices for interacting with users. Examples of output devices include displays, speakers, vibration and/or other haptic devices, and so on. Examples of input devices include keyboards, computer mice, buttons, dials, knobs, joysticks, microphones, track pads, track balls, touch screens, touch sensors, touch pads, and so on. Some input devices include a structure that is moveable by a user to provide input.
For example, input devices such as watch crowns or joysticks may include a shaft that can be moved in one or more ways. An input device may include various mechanisms for detecting and/or measuring movement of a shaft. For example, movement of a shaft may connect and/or disconnect one or more sets of electrical contacts. As another example, a shaft may be moved to exert and/or relieve pressure on one or more dome switches. In yet another example, movement of a shaft may compress dielectric gel to move electrodes of one or more capacitive sensors with respect to each other.